Using a psychosocial model of youth self-esteem, this application proposes (a) a 2-year, four-wave prospective study of self-esteem and its psychological, ecological, and adaptive correlates during the transition from childhood to adolescence and (b) the design of a prevention program to enhance self-esteem and reduce rates of disorder among young adolescents. The sample (n = 400) for the prospective study will consist of equal sized cohorts of preadolescents (5th/6th grade) and early adolescents (7th/8th grade), with stratified sampling for gender, race/ethnicity, and family low-income status. Youths will be assessed during the fall and spring semesters of two consecutive school years using measures of self-esteem, ecological experiences (social support, positive/negative events, extracurricular involvements), self-system processes (self-concept, self-standards, self-values), and adaptation (emotional, behavioral, academic). Semi-structured interviews will be conducted with a subsample of youths (n = 32) selected for low and high self-esteem. Specific aims are to: (1) investigate change and stability in self-esteem during pre-adolescence and early adolescence, including both longitudinal trajectories and short-term (day-to-day) lability in feelings of self-worth; (2) further validate and refine the PI's psychosocial model, including the relationship of self-esteem to (a) experiences in primary domains of development (i.e., school, peers, and family), (b) conceptually-related aspects of the self-system (i.e., content-specific evaluations of the self, descriptive views of the self, standards for the self, self-values, and racial/ethnic identity), and (c) socioemotional and academic adjustment, including transactional (bi-directional) patterns of linkage and both depression and specific health-risk and problem behaviors; and (3) address methodological limitations of prior research through the use of a multiple wave prospective design, a demographically diverse sample of youth, multidimensional measures of trait and state aspects of self-esteem, multi-source assessments of self-esteem and adaptive outcomes, structural modeling with latent variables, and qualitative interview data to augment quantitative measurements. Specific aims of the second component of the research are to: (1) design an esteem-enhancement program for older children and young adolescents that is grounded solidly in relevant theory and empirical knowledge, including the findings of the proposed prospective study; (2) enhance and refine the design of the program through consultation with leading scientists in the prevention area, feedback from administrators with expertise in youth program development, and focus groups/informal piloting with youth, parents, and teachers; and (3) plan a grant-funded (competing continuation) experimental study of the program's effectiveness.